This week the goal is to redraw the Echo hello board using any circuit design software and add atleast an LED and a push button to it. The Echo hello board is shown below.
The software I am using to redraw the circuit is Eagle by
Autodesk. It is a freeware and is available for download from autodesk
homepage.
After installing the software I went through some online tutorial videos
that help me understand the placing and connecting of various components.
It was also necesaary to load the Fab Library to the software so that
one could add the components that are available in the lab.
For this the Fab library
is provided by the Fab Academy. Copy the text into a new text file
and rename as "fab.lbr". Now copy this file in the lbr folder
of Eagle software.
Since an LED was to br added to the ciruit , the current through it has to be balanced. For this a resistance is to be used. To calculate the value of the resistance use the formula V=IR (Ohm's law). I used a 499ohm resistor for my LED.
For Designing, open Eagle. Then create a New Project and select Schematic
Go to Libraby and select Fab library. All the components available
in the lab will be showcased in that library.
Browse all the components from the library and add them one by one. Place
is in a way that connecting the components become easy.
Connect all the componets according to the schematic
After all the components are connected, recheck for errors and proceed towards
Route generation.
Set the design rules according to the tolerances of the machine
Arrange the components at suitable distances and select auto routing
Look for 100% efficiency and select the design.
When the route is generated select another layer to draw the route for cutting the PCB
Export both trace and cut files as different png files into a folder. These are to be saved as monochrome so that Fab module can read it.
After PCB milling there was an error I noticed in the circuit design before soldering
There is a tool in Eagle for checking the errors in the schematic and also the board design. I had run the error check but I unknowingly missed the part where the software mentioned the error in the design. I accidently skipped the error and proceeded with the design. I later run the error report again to check the actual problem with the schematic. Below is the screenshot of the error.
The circuit was later removed using paper cutter
The original design files can be downloaded from below
